Solvents derived from petrochemicals are commonly used to extract flavor and fragrance materials from botanical sources for use in adding aroma to consumer products. Solvents are also used to dissolve essential oils. Environmental, market, esthetic and other factors have recently led to desire on the part of consumers and producers for alternatives to petrochemicals as sources for solvents and other components in a variety of products.
The “Common Fragrance and Flavor Materials” (Preparation, Properties and Uses, 5th Ed. Horst Surburg and Johannes Panten Copyright© WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) discloses methods for the isolation of natural fragrance and flavor concentrates. Major methods used to concentrate flavor and fragrance materials include distillation, mechanical separation and solvent extraction.
Essential oils can be obtained by distillation of plant materials with water or steam. After condensation of the water phase, the water separates from the essential oils. The essential oils can be used directly as starting material for flavors and fragrances or can be highly diluted with certain solvents. Distillates can be obtained by the distillation of plant materials with water-ethyl alcohol mixtures, and the products of the distillation contain ethanol. Alcohol, however, is not desirable for some products, and can cause skin irritants for some individuals. While an aqueous solvent would be desirable, many essential oils and other botanical materials are not water-soluble. There are certain plant materials (e.g. jasmine) for which distillation cannot be used successfully because the heat treatment would deteriorate the aroma materials; therefore solvent extraction is used to obtain flavor and fragrances from such plants.
It is generally desirable to avoid the use of volatile organic compounds (VOC) in products such as personal care products. Also other petrochemical solvents are broadly used for plant extraction as hexane, toluene and petroleum ether. These solvents, though are effective to extract flavor and fragrance materials from plants, but can be difficult to remove completely, and therefore the final products can contain undesirable odor and harmful or toxic ingredients, and may cause skin irritation or other health related problems.
Water-based microemulsions containing perfumes or flavors, have been developed, as disclosed, for example, in U.S. Pat. No. 6,403,109. However, microemulsions rely on the use of large amounts of surfactants, which also may be undesirable for some consumer products. Silicones, which are also present in the emulsions disclosed in U.S. Pat. No. 6,403,109, may also be undesirable in some products.
A need remains for materials that are non-petroleum based, non-volatile, non-toxic, non-hazardous and biodegradable, and have high efficacy to extract flavor and fragrance materials from plants and to solubilize essential oils and other botanical extracts for use in consumer and industrial products. It is also desirable to have methods that are simple and safe, and eliminate the need for removal of high VOC petroleum based solvents. It is further desirable to be able to use renewably sourced and biodegradable materials in consumer and industrial products containing botanical extracts.